1. Field of Invention
The present invention relates to apparatus, components and the like, which carry out information communication (signal transmission) between a plurality of apparatus or within an apparatus and the like, by using an optical signal.
2. Description of Related Art
Acceleration of a signal transfer rate between circuit chips or between circuit boards and the like included in various apparatus has advanced, and thus problems of cross talk between signal lines, noise radiation, impedance mismatching, high power consumption and the like are becoming critical. For this reason, optical communication is beginning to be introduced even for signal transmission inside an apparatus. Furthermore, a method of transmitting an optical signal through an optical fiber (tape fiber) or an optical waveguide, instead of other methods of running electric signal in metal wiring, between circuit chips and between modules and the like inside an apparatus, is being employed.
When carrying out optical communication, it is important to precisely align the mutual positioning (optical-axis alignment) at nodes, which exist on a transmission path of the optical signal, for example, between optical fibers, and between an optical fiber and a light-emitting element or a photo detector to avoid increase in optical coupling loss. Thus, in order to accomplish these demands, various techniques have been employed. For example, for a multi-core optical plastic connector which is used when coupling a plurality of optical fibers, in case of employing a structure having an intruding pin provided on one of connectors, while a fitting hole, in which the intruding pin is to be inserted, is provided on the other connector, a technique of enhancing precision of the bore diameter of the fitting hole by forming the fitting hole with metal or ceramic, and thus enhancing the positioning precision between fibers has been disclosed.